A gas bag covering system is known from the DE 296 03 316.2. The gas bag covering here represents the lining of the vehicle roof. In the region of the roof frame a profiled mounting clip is fastened to the roof frame itself. This mounting clip has an arm which is hook-shaped in profile and engages the outer edge of the lining. On unfolding of a head/side gas bag which is fastened between the gas bag covering and the roof frame, an outer portion of the gas bag covering folds downwards. For this, the outer edge of the covering springs out from the hook-shaped arm of the mounting clip. Upon opening up of the gas bag covering, the gas bag unfolding opening is exposed, so that the gas bag can extend through it and along the window of the vehicle. On the one hand, the fastening device must fix the lining securely to the vehicle for normal traveling, on the other hand it must not be allowed to offer too great a resistance to the opening of the covering to expose the gas bag unfolding opening. This would in fact impede the unfolding process. In fact at low temperatures, the device, which usually consists of plastic, will however provide for such a high resistance.